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INSTALLATION MANUAL

Specifications, retrofit installation, MCU wiring, button configuration, synchronized furling operation, troubleshooting and maintenance for the Selden SMF retrofit on an existing 12/24 V electric RB or RC furling mast.

DocumentSelden SMF Retrofit on 12/24 V Electric System, RB & RC Installation Manual
FormatPDF · 24 pages · 4.6 MB
LanguageEnglish
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OverviewSpecificationsInstallationWiring & ButtonsBefore SailingOperationTroubleshootingMaintenanceProducts
Selden SMF Retrofit on 12/24 V Electric System, RB & RC — Installation Manual

Synchronized Main Furling (SMF) Retrofit

The SMF retrofit kit (electric mast motor and shaft assembly) upgrades an existing 12/24 V electric drive unit on RB and RC furling masts, mast sections R232, R260, R290, F228, F246, F265, F286, F305, F324. The motor fits inside the existing cover and is run by the Selden Power Supply and SEL-Bus system together with a Selden electric winch for synchronized outhaul (both sold separately).

  • The mast ID is engraved on the port side at the bottom of the mast extrusion; the motor part and serial numbers are on its aft side, facing the sail groove. Quote all three in any support case.
  • Related documents: 597-275-E (installation of Power Supply and SEL-Bus), 597-283-E (order guide), 595-540-E (Hints and Advise).
  • Network: battery, main switch/fuse, PSU (converts 12/24V to 42V), SMF push buttons, electric winch with its MCU and push buttons, mast motor with its MCU, SEL-Bus backbone cables.

Turn off the power during installation and when the system is not in use. Always watch the whole furling process and stop immediately if anything goes wrong. Keep hands clear of the sail groove and winches.

Technical Specification

Furlin system RB OUT RB IN RC OUT RC IN
Total gear ratio 81:1 81:1 81:1 81:1
Peak torque 8Nm 89Nm 16Nm 170Nm
Low speed (max) 49 RPM 37 RPM 37RPM 37RPM
High speed (max) 74 RPM 74 RPM 74RPM 74RPM
Max power (full torque) 144W 600W 175W 740W
Full load current* 12V - 50A - 60A
Full load current* 24V - 23A - 29A
Nominal current* 12V 12A 16A 15A 20A
Nominal current* 24V 5,5A 7,5A 7,5A 10A
Synchronized winch: limited outhaul force (OUT) 1800N 2200N
  • *Consumption incl. MCU and PSU.
  • The outhaul force is limited only when the winch runs on the MAIN "OUT" button; on winch buttons "1" and "2" it runs as a standard, unlimited, unsynchronized winch.
  • Mast motor and clutch assembly: H 252 mm, W 102 mm, 4,2 kg; fits inside the mast section.

Retrofit Installation

Tools: flat screwdriver, Torx and hex key sets, pliers, power drill, Ø10.2 mm drill bit, Ø19 mm countersink, 20 mm hole saw, pencil, tape measure, heat gun and shrink tube, cleaning spirit and cloth, medium-strength locking adhesive, adhesive tape, a 150x1000mm board 10-15mm thick to support the motor, marine adhesive sealant. Release backstay tension first.

  1. Insert the emergency handle, push in and turn clockwise to engage the worm gear; turn the clutch handle to disengage the luff profile from the motor.
  2. Remove the port-side access cover and grease plug.
  3. Through the lower access hole, unscrew the retainer screw and push the locking tube above the sail feeder; hold it up with tape.
  4. Hold the luff profile through the upper access hole, push the emergency handle in and turn anticlockwise to release luff tension.
  5. Through the lower port greasing hole, remove and keep the split pin and clevis pin from the gear shaft adapter.
  6. Turn the handle anticlockwise again to separate tack assembly and clutch; remove the handle.
  7. Support the motor from below, remove the clutch and motor screws, then the cover screws, and lift out clutch and motor.
  8. Drill 2 new holes in the cover for the new motor unit, and ø20mm holes in the mast wall for motor support and lubrication access (instruction 597-846). Grind the edges.
  9. Fit clutch (temporarily) and new motor to the cover with marine sealant or anti-corrosion compound in the new holes; check the clutch.
  10. Replace the old electric cables with new.
  11. Remove the upper clutch screws (A) and loosen the lower ones (B) 3-4 turns to ease fitting.
  12. Fit the cover with motor and clutch without damaging cables; fit all screws with Loctite.
  13. Reconnect the luff extrusion and tension the luff profile.

Connecting to the MCU

Connect the three control cables from the mast motor to the MCU "Furling mast" in the correct positions: L1 = Brown, L2 = Orange, L3 = Grey. Wrong positions can damage the mast motor and brake mechanism. Full MCU and network installation: manual 597-275-E.

Configuring the Buttons (in this order)

  1. Winch MCU to winch buttons: press the configuration button on the winch MCU, then hold winch button 1 or 2 until the winch gives the start-up signal.
  2. Winch MCU to MAIN OUT (synchronized outhaul): press the winch MCU configuration button, hold MAIN OUT until the start-up signal.
  3. Furling mast MCU to MAIN OUT/IN: press the furling mast MCU configuration button, hold IN until the mast motor gives the start-up signal.

If the signal tone sounds when the system is switched on with no button pressed, switch off at once: the push button cables from the SEL-Bus converter must be wired "normally open", not "normally closed".

Preparations Before Sailing

  • Luff extrusion tension: an untensioned or over-tensioned extrusion raises furling load and wear. Stop the extrusion rotating and measure the tensioning torque with a torque wrench in the winch handle socket (or a spring balance on an ordinary winch handle); keep the mast straight. Always release the backstay first: tensioning with the backstay on can damage the extrusion joints when it is released.
  • Rig tuning: furling works best with limited pre-bend (595-540-E).
  • Outhaul car stop: too far aft keeps the foot tighter than the leech and can jam the sail at the top of the mast. Start with the stop 500 mm from the aft mast wall and adjust.
  • Outhaul routing: as low friction as possible; replace worn blocks. The winch force limit acts on line force at the winch, so friction lowers the force at the clew and hurts synchronization.

Unfurling

  • Before furling in or out: adjust boom angle, ease the main sheet, release the backstay, keep the sail head to wind; avoid reefing to a point where battens ride on the sail slot.
  1. Put the outhaul on the synchronized electric winch.
  2. Press OUT: the winch gives a short warning signal before starting.
  3. Hold OUT and press the second button for more speed if wanted.
  4. Full sail: hold the button(s); the system recognises a fully unfurled sail and stops. Reduced sail: release when the sail is where you want it.
  5. Trim the outhaul with the winch buttons if needed (full winch power: take care).

The motor makes a short rotation after unfurling to engage the brake.

Furling & Manual Outhaul

  1. Free the outhaul but keep it tensioned (about one turn on the winch). Press IN and ease the outhaul as the sail rolls in.
  2. Hold IN and press the second button for more speed.
  3. Release at the desired sail area or when fully furled.

The motor does NOT stop automatically when furling in. Run the last turns at low speed and watch the outhaul block so it is not pulled into the sail groove.

Without the synchronized winch: hold MAIN OUT and pull the outhaul by hand; the motor pauses if the outhaul is not pulled, and turns when it detects pull. Releasing OUT engages the brake.

Troubleshooting

Problem Cause Action
Mast motor stutters and unfurling does not work Connection cables wrongly installed in the MCU Correct the cable positions in the MCU
Constant signal tone at power-on; or motor runs at power-on and stops when MAIN OUT/IN is pressed Push button cables wired "normally closed" Rewire to "normally open" (see push button sheet)
Synchronized unfurling not smooth / top of sail jamming Luff tension, rig tuning, outhaul car position, outhaul routing See Preparations Before Sailing
Unfurling unusually slow in cold conditions Cold motors Disconnect the mast motor from the manual gear, take the outhaul off the winch, idle-run the mast motor IN and the winch on high speed, minimum 30 sec each

Service, Maintenance & Warranty

  • Keep the manual furling system serviced as per the furling mast manual.
  • Annually – lubricate the motor brake: through the starboard hole remove the lubrication hole screw (guard it from dropping between mast wall and motor), apply WD-40 while turning the mast motor at least one turn, refit the screw.
  • Every 5th year: professional service of the mast motor by an authorised Selden dealer.
  • Warranty: 2 years, valid only if assembled, operated and maintained per this manual; void if repaired or modified by anyone other than Selden or its authorised dealers.
  • Dispose of as electrical and electronic equipment (WEEE), not household waste.

Need a part that isn't listed? Ask us to source it and quote the part number from the PDF.

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